This is a revision of a renewal application for a project known as the Victoria Longitudinal Study (VLS). A prospective study underway for over 20 years, the VLS has operated effectively and productively for the last decade in two coordinated labs. The general objective of the VLS is to examine actual short- and long-term changes in middle-aged and older adults across many domains of cognition as they are dynamically influenced and modified by multiple aspects of health (e.g., conditions, beliefs), biological attributes (e.g., functional, genetic), lifestyle activities (e.g., cognitive, social, physical engagement), and neuropsychological status (e.g., cognitively successful, normal, cognitively impaired). According to our Research Plan, we collect systematic, multivariate, and comprehensive data on long-term volunteer participants through repeated waves of observation at regular intervals (every 3-4 years, with 10-12 hours of testing at each wave). Since its inception, the VLS follows a design that features three initially healthy sequential samples (all initially aged 55-85 years, now about 63-100+ years). The three samples were begun in adjacent decades (1980s, 1990s, and 2000s). The VLS now has longitudinal data that span a gradient of 40 years of aging, plus numerous control (e.g., younger, middle-aged adults) and emerging target and comparison groups (e.g., Type 2 diabetes, Mild Cognitive Impairment). The current Specific Aims are to (a) continue the systematic assembly of a rich data archive on actual cognitive changes with aging, (b) identify key patterns of cognitive differences, changes, and transitions with aging, and (c) investigate theoretically and clinically relevant precursors, correlates, and modifiers of healthy, normal, and impaired changes with aging. We report substantial progress in pursuing these aims in the recent grant period. Our Proposed Research includes (a) continued collection of critical waves of longitudinal data, (b) development and management of all longitudinal and comparison samples, and (c) new research in four integrative themes of contemporary cognitive aging. Each proposed theme involves innovative studies on (a) independent and interacting influences (e.g., health, lifestyle, genetic, functional across (b) multiple domains of reliably measured cognitive change (e.g., declarative memory, executive function, speed and inconsistency) using (c) well-characterized and large samples of broad age-bands of adults who may be (d) representative of theoretically and clinically interesting health groups of significance to aging, and are always (e) followed carefully across longitudinal waves. The General Significance of the VLS lies in its ever-growing rich, unique, and multi-faceted data set on actual changes in human aging. A more specific significance pertains to the increasingly integrative studies showing both independent and interactive influences on cognitive aging trajectories and outcomes. The research we conduct addresses historically valid and currently compelling empirical, theoretical, and practical issues of health and aging.